Altered in utero kidney development in newborns with congenital heart disease

Engineered human iPS cell models reveal altered podocytogenesis and glomerular capillary wall in CHD-associated SMAD2 mutations

Early developmental programming involves extensive cell lineage diversification through shared molecular signaling networks. Clinical observations of congenital heart disease (CHD) patients carrying SMAD2 genetic variants revealed correlations with multi-organ impairments at the developmental and functional levels. For example, many CHD patients present with glomerulosclerosis, periglomerular fibrosis, and albuminuria. Still, it remains largely unknown whether SMAD2 variants associated with CHD can directly alter kidney cell fate, tissue patterning, and organ-level function. To address this question, we engineered human iPS cells (iPSCs) and organ-on-a-chip systems to uncover the role of pathogenic SMAD2 variants in kidney podocytogenesis. Our results show that abrogation of SMAD2 causes altered patterning of the mesoderm and intermediate mesoderm (IM) cell lineages, which give rise to nearly all kidney cell types. Upon further differentiation of IM cells, the mutant podocytes failed to develop arborizations and interdigitations. A reconstituted glomerulus-on-a-chip platform exhibited significant proteinuria as clinically observed in glomerulopathies. This study implicates CHD-associated SMAD2 mutations in kidney tissue malformation and provides opportunities for therapeutic discovery in the future.

Model-Informed Vancomycin Dosing Optimization to Address Delayed Renal Maturation in Infants and Young Children with Critical Congenital Heart Disease

Ensuring safe and effective drug therapy in infants and young children often requires accounting for growth and organ development; however, data on organ function maturation are scarce for special populations, such as infants with congenital diseases. Children with critical congenital heart disease (CCHD) often require multiple staged surgeries depending on their age and disease severity. Vancomycin (VCM) is used to treat postoperative infections; however, the standard pediatric dose (60-80 mg/kg/day) frequently results in overexposure in children with CCHD. In this study, we characterized the maturation of VCM clearance in pediatric patients with CCHD and determined the appropriate dosing regimen using population pharmacokinetic (PK) modeling and simulations. We analyzed 1,254 VCM serum concentrations from 152 postoperative patients (3 days-13 years old) for population PK analysis. The PK model was developed using a two-compartment model with allometrically scaled body weight, estimated glomerular filtration rate (eGFR), and postmenstrual age as covariates. The observed clearance in patients aged ≤ 1 year and 1-2 years was 33% and 40% lower compared with that of non-CCHD patients, respectively, indicating delayed renal maturation in patients with CCHD. Simulation analyses suggested VCM doses of 25 mg/kg/day (age ≤ 3 months, eGFR 40 mL/min/1.73 m2 ) and 35 mg/kg/day (3 months < age ≤ 3 years, eGFR 60 mL/min/1.73 m2 ). In conclusion, this study revealed delayed renal maturation in children with CCHD, could be due to cyanosis and low cardiac output. Model-informed simulations identified the lower VCM doses for children with CCHD compared with standard pediatric guidelines.

Birthweight and isolated congenital heart defects - A systematic review and meta-analysis

Background

Birthweight (BW) is an important prognostic factor in newborns with congenital heart defects (CHD).

Objectives

To give an overview of the literature on BW z‐score in children with isolated CHD.

Search strategy

A systematic search was performed on isolated CHD and BW in PubMed, Embase, Web of Science, COCHRANE Library and Emcare.

Selection criteria

Neonates with isolated CHD were included if a BW percentile, BW z‐score or % small‐or‐gestational age (SGA) was reported.

Data collection and analysis

BW z‐score and percentage SGA were pooled with random‐effect meta‐analysis. Quality and risk of bias were assessed using the modified Newcastle Ottawa Scale.

Main results

Twenty‐three articles (27 893 cases) were included. BW z‐scores were retrieved from 11 articles, resulting in a pooled z‐score of −0.20 (95% CI −0.50 to 0.11). The overall pooled prevalence of SGA <10th percentile was 16.0% (95% CI 11.4–20.5; 14 studies). Subgroup analysis of major CHD showed similar results (BW z‐score −0.23 and percentage SGA 16.2%).

Conclusions

Overall BW in isolated CHD is within range of normality but impaired, with a 1.6‐fold higher risk of SGA, irrespective of the type of CHD (major CHD vs all CHD combined). Our findings underline the association between CHD and BW. The use of BW z‐scores provides insight into growth of all fetuses with CHD.

Tweetable abstract

Infants with a congenital heart defect (CHD) have a lower birthweight z‐score and a higher incidence of small‐for‐gestational age (<10th percentile). This was encountered both in the major CHD‐group as well as in all‐CHD combined group analysis. Future research on the association between birthweight and CHD should include all types of CHDs (including mild cardiac defects) and placental‐related disease, such as pre‐eclampsia. We advocate the use of international standardised fetal growth and birthweight charts in CHD research.

Infants with a congenital heart defect (CHD) have a lower birthweight z‐score and a higher incidence of small‐for‐gestational age (<10th percentile). This was encountered both in the major CHD‐group as well as in all‐CHD combined group analysis. Future research on the association between birthweight and CHD should include all types of CHDs (including mild cardiac defects) and placental‐related disease, such as pre‐eclampsia. We advocate the use of international standardised fetal growth and birthweight charts in CHD research.